Whatever the causes of the smog, by one ranking Delhi was not just the most polluted city in the world, but “nearly five times as bad as the second most polluted city, Dhaka,” in Bangladesh next door, as Shashi Tharoor, a leader of the opposition in Parliament and best-selling author, posted on X.

State authorities tout an experimental plan that involves stimulating clouds for rain, but scientists are sceptical.

In several areas of the city, pollution levels were more than 50 times higher than the World Health Organization’s recommended safe limit. Forecasts say the poor air quality will continue into the week.

Hundreds of millions of Indians breathe some of the world’s most toxic air all year round. Air pollution in the capital area that’s home to about 30 million people is especially stubborn. In winter, the cold weather actually makes the smog even worse — and potent.

Unhealthy

India's capital was left gasping this week as air pollution smog reduced visibility to near zero and raised air quality levels more than 130 times safe limits.

Most of India’s coal-burning plants are set to again fall short of a major pollution target, adding to the deadly smog that’s enveloped large parts of the country.

Pollution levels in Chandigarh - India's first planned city, located about 240km (150 miles) from capital Delhi - have been at more than 15 times the safe limit recommended by the World Health Organization (WHO) for more than a month.

Strong surface winds (at speeds of 15km/hr) that had helped disperse pollutants on Sunday, dropped to near-calm levels of 4-6km/hr by Monday morning, leading to a haze engulfing the city again. Delhi’s 24-hour average air quality index (AQI) was recorded at 285 (“poor”) at 9am on Monday,